Fuel burner structure

ABSTRACT

An oven having a fuel burner which achieves space-saving and economy by combining the burner body with a floor shield.

United States Patent 11 1 11 3,739,766 Helgeson- 1 June 19, 1973 [54] FUEL BURNER STRUCTURE 2,242,|76 5/1941 Denise 239 557 x 3,526,367 9/1970 Trihc 239/556 [75] Inventor: Peter L. Helgeson, Macungle, Pa. 3.436.166 W969 grickg'onu 431/354 [73] Assignee: Raytheon Co pany, Lexin to 3,295,509 l/l967 Harvey 126/25 Mass.

[ Filedl 1972 Primary Examiner-Edward G. Favors Attorney-Harold A. Murphy, Joseph D. Pannone, 21 A LN 229 424 l 1 pp 0 Edgar O. Rost et all.

[52] U.S. Cl 126/19 R [51] Int. Cl A2lb 1/00 [57] ABSTRACT [58] Field'of Search 126/39, 41, 25, 275,

I 113/116 EE An oven having a fuel burner which achieves spacesaving and economy by combining the burner body [56] References Cited with a floor shield.

UNITED STATES PATENTS 2,470,880 9 Claims, 10 Drawing Figures 5/1949 Zimbelman et al 239/556 Patented June 19, 1973 4 Shoots-Sheet 2 Q OOC/QOOO OOOOOO Patented June 19, 1973 3,739,766

4 Sheets-Sheet 3 Patented June 19, I973 3,73,76

4 Shoots-Sheet 4 O00OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO FUEL BURNER STRUCTURE BACKGROUND OF THE INVENTION Gas ovens conventionally comprise a compartment in which baking or broiling can occur. The oven compartment contains in its upper extremity a broiler burner, while a bake burner is located beneath the oven bottom. The bake burner is usually positioned between the oven bottom and the floor shield so as to direct heat by convection up through openings in the oven bottom onto and around food to be heated.

It will be apparent that such a construction occupies a relatively large amount of space especially when bulky conventional burners are employed, and space is at a premium in ovens such as the built-in type, for example. Such a conventional structure, of course, limits the overall size of the oven which may be required to be fitted into a preshaped opening. Furthermore, thecost of making and mounting several separate components such as burners, venturis and floor shields, for example, can be relatively great.

Attempts have been made to overcome some of these problems such as, for example, the structure disclosed by H. L. Frick in U. S. Pat. No. 3,247,838. However, such attempts as Frick have usually resulted in rather complicated structures employing intricately produced parts and, therefore, relatively expensive to fabricate and assemble. Frick, illustratively, combines a burner with a floor shield and produces a broad flame which is intended to overlie the bottom surface of the floor shield. Consequently, the floor shield prevents ready passage of heat into the oven compartment, especially during the initial moments of a baking cycle until the shield becomes heated to radiating temperatures.

v SUMMARY OF THE INVENTION The present invention overcomes the above and other disadvantages of the prior art by the provision of a burner which is combined with a floor shield in such a manner that conventional ported blue flames are produced above the floor shield for efficient passage of heat by convection into the oven compartment. ln accordance with this invention the floor shield forms the bottom of a burner box, and includes a stamped out venturi as an integral part.

In one form of the invention the flame ports are stamped out of a peripheral flange portion of the burner box or body, with adjacent openings being provided through the floor shield for supplying oxygen to the flames. In a modification, the ports are formed in a side wall of the box at a level above the floor shield so that efficient circulation of secondary air is provided to the flames.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features of the invention will become apparent from the following description taken in connection with the accompanying drawings, wherein:

FIG. 1 is a vertical sectional view in somewhat diagrammatic form through an oven embodying the invention;

FIG. 2 is a fragmentary plan view of the combined floor shield-burner of the invention;

FIG. 3 is a side elevational view of the device shown in FIG. 2;

FIG. 4 is an enlarged sectional view of a portion of the device of FIG. 3 showing one means for clamping parts together;

FIGS. 5 and 6 are side elevational and plan views respectively of a modified form of the invention;

FIGS. 7 and 8 are side elevational and plan views respectively of a further modification in the invention; and

FIGS. 9 and 10 are side elevational and plan views respectively of a still further embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the invention illustrated in FIGS. 1-4, there is disclosed an oven of a type wherein a single compartment is utilized for both broiling and baking. The oven is diagrammatically illustrated as including a boxlike structure having an inner liner 10 supported within suitable insulated framework and including the usual access door 12. A broiler burner 14 of any suitable type is supported from one of the walls 16 in the upper regions of the compartment, as well as a suitable adjacent igniter 18. The lower region of the compartment is traversed by a bottom 20 of sheetlike metal upon which may be placed food to be heated. The oven bottom or support 20 is preferably removably mounted along marginal portions as by being freely set upon inturned portions 22 of the liner 10, for example. The bake burner 24 is mounted beneath the oven bottom 20 as will be described and in operation will function to heat the surrounding air which flows upwardly through openings 26 provided for the purpose in bottom 20. Thus, heated air will envelop the food and will continue to circulate through the oven and eventually exhaust through vent 28.

The .complete burner structure 24 of this invention includes a sheetlike metal plate 30 which normally functions as a floor shield and which extends at least partially across the lower end portion of the oven compartment as a shield which protects cabinetry, flooring or the like beneath the oven from becoming overheated. This floor shield 30 is shown as being removably supported at opposite edges upon embossments 32 or flanges provided on the oven liner 10, but may be supported in any other suitable manner and, if desired, may be provided with angled side portions for deflecting heated air upwardly. Shield 30 may also be provided with openings for introduction into the compartment of fresh air to be heated and circulated.

The burner 24 in the embodiment of FIGS. 2 and 3 is an open-bottom metal box 34 formed of sheet metal, cast iron or other suitable material capable of resisting deformation when subjected to the temperatures incurred in gas or liquid fuel burners. The burner box 34 is disposed with its open side down on the upper surface of the floor shield 30. The burner box 34 is provided throughout the periphery of its open side with an outstanding flange 36 which rests upon the floor shield and by which the box may be fixed to the floor shield when welded connections therebetween are employed. If desired, suitable refractory gasketing (not shown) may be used between the flange 36 and floor shield 30.

The flange 36 is provided with a plurality of spaced regions which are raised out of contact with the floor shield 30 to form ports 38 at the outer ends of which flames may be produced in the operation of the device as will be described. Such porting may be constructed by a suitable die pressing or stamping process during fabrication of the burner box, and the ports 38 may be of any selected size depending upon the size of the individual flames to be produced and the air-gas mixtures and pressures being utilized.

The combustible fuel mixture is supplied to the burner by a conduit 40 and nozzle 42, which conduit is connected at one end to a fuel supply by means not shown. The nozzle or jet 42 on the other end of the conduit 42 is directed freely into the open end of a mixing tube or venturi 44 which is formed as by stamping or striking out of the floor shield burner box 34 as shown in FIG. 3 or, alternatively, out of the floor shield 30 as shown by dotted lines in FIG. 3. The venturi 44 communicates with the interior of the burner box and thus supplies a controlled fuel-air mixture into the burner box in a known manner, which mixture becomes ignited as it passes out of box 34 through ports 38. An igniter 46 of any suitable type is located adjacent the burner 24 for igniting the gas-air mixture flowing from the ports in the usual manner. The igniter 46 should, of course, be located close enough to at least one of the ports 38 so that efficient ignition will take place at the adjacent port or ports, and the individual ports should be spaced close enough to adjacent ports so that ignition will readily occur from one port to another.

Although in the foregoing description mention has been made that the burner box 34 is fixed to floor shield 30 as by welding portions of the flange thereto, mechanical means may be provided for this purpose if desired. One such means is shown in FIG. 4 wherein a bracket 48 is fixed to the upper surface of the floor shield 30 and a screw 50 and nut 52 are used to secure the box 34 to the bracket 48 for easy removal of the box for servicing or cleaning. It is highly desirable for obvious reasons that efficient contact of the flange 36 be made with the floor shield 30 so that gas will not escape from the box except through the ports. Gasketing (not shown) may be desirable to assist in this respect.

In order to supply secondary air to the burner it may be necessary to provide a series of openings 54 through the floor shield 30 adjacent the flange 36. This may be necessary particularly where the ports 38 are disposed closely to the floor shield 30.

In the modification of the invention shown in FIGS. and 6, the burner box 56 is formed as a depressed area in the floor shield and is covered by a burner cap 58 which overlies the burner box with its peripheral or marginal edge portions slightly overlapping and resting upon the upper surface of the floor shield 30 around box 56. The edge portions of the burner cap 58 are made to closely engage the floor shield 30 and are affixed thereto as by welding. At spaced intervals throughout the margin of the burner cap 58 raised areas 59 are provided, as by a die pressing or stamping operation, to provide a series of ports 60, similar to the ports 38 in the structure of FIG. 3.

At one end of burner box 56 an integral venturi 62 is also struck out of the metal of the floor shield as shown best in FIG. 5, one end of the venturi communicating with the interior of the burner box 56 so that a controlled fuel-air mixture can be introduced into the burner box. Cap 58 is provided at one end with an extension 63 for closing the upper side of the venturi 62.

Openings or slots 64 may be provided in the floor shield adjacent the ports 68 to provide secondary air for combustion purposes.

In the embodiment shown in FIGS. 7 and 8, the burner box 66 is struck out of the floor shield 30, somewhat similar to the burner box 56 of FIG. 5. However, box 66 is relatively shallow in depth and when box 66 is being formed, as by die pressing or stamping, a raised area or ridge 67 is formed around the box 66. A burner cap 68 somewhat similar to cap 60 is disposed in overlying relation to the box 66 and is provided throughout its periphery with a downwardly angled flange or rim 70 which rests upon the raised rim 67 and is affixed thereto, as by welding, and forms a cover for the burner box 66. Burner ports are formed by stamping out spaced raised portions 71 of the burner cap 68 around the edge thereof adjacent the area which is in contact with the rim 67.

In this embodiment, the burner box extends both above and below the floor shield and thus the ports are spaced somewhat above the floor shield so that secondary air can flow to the ports over the surface of the floor shield without requiring openings therefore in the floor shield.

A venturi 74 is formed by stamping out adjacent portions of both the burner cap 68 and the floor shield 30, which portions are dimensioned to mate with one another and are secured to one another in a desirable manner to complete the assembly.

In the further embodiment illustrated in FIGS. 9 and 10, the burner box 76 is formed by stamping the floor shield 78 upwardly so that the main portion of the box appears as a raised portion of the shield. One end of such raised portion or box 76 has an integral extension 80 which forms a major portion of a venturi. The lower side of the burner box 76 is closed by a flat plate 82 which is secured as by welding around its margin to the under side of the floor shield 78. The plate 82 also closes the bottom side of the venturi 80. A series of openings 84 in the side walls of the burner box 76 function as ports for production of blue flames in the normal operation of a device of this character. Ports 84 are spaced upwardly from the major plane portion of the floor shield 78 so as to allow secondary air to pass to the ports for combustion purposes.

Although the invention has been illustrated as applied to a lower or bake burner, it will be understood that it could be utilized as an upper or broil burner by inverting it and providing a broad shield which extends across the upper end of the oven compartment similar to the floor shield described.

It will be apparent from the foregoing that a novel, efficient and economical burner structure has been provided by combining a floor shield with a burner box in the manner described. Accordingly, not only is a cost saving achieved but a reduction in the overall space required by conventional structures is accomplished.

It will be apparent that various modifications and changes may be made by those skilled in the art without departing from the spirit of the invention as expressed in the accompanying claims. It is to be understood, therefore, that all matter set forth and described is to be interpreted as illustrative and not in a limiting sense.

I claim 1. An oven including a compartment defined by walls, a gas-fueled burner in said oven comprising a refractory sheet extending across a major portion of the oven and mounted on said walls, a burner box having an open side with a flange extending outwardly therefrom, said box being secured to said sheet with the flange effectively engaging the sheet and the sheet closing the open side of the box, ports in said box communicating with the interior of the box, venturi means communicating with the interior of the box, and conduit means carried by the oven and having one end disposed adjacent said venturi for delivering fuel to the venturi and consequently to the burner.

2. An oven as set forth in claim 1 wherein said ports are located between'said sheet and flange.

3. An oven as set forth in claim 1 wherein said box and sheet are of sheet metal, and said ports comprise stamped portions of the flange.

4. An oven as set forth in claim 1 wherein said venturi means comprises at least in part a projecting portion of said box.

5. An oven as set forth in claim 1 wherein said box and sheet are both sheet metal members, and said venturi means is an integral stamped part of one of said members.

6. An oven as set forth in claim 1 wherein said burner box is a stamped sheet metal member and the venturi means is an integral stamped part at one end thereof, one side of the venturi means being open and continguous with the open side of the box and closed by said sheet, and said flange having spaced portions thereof raised out of engagement with the sheet to provide said ports.

7. An oven as set forth in claim 1 wherein said oven walls include a front wall having a door therein, said walls, back and top walls, and an oven bottom spaced upwardly from the lower end of the compartment, and said sheet comprises a floor shield with the burner box located on it between the sheet and the oven bottom.

8. An oven including a compartment defined by walls, a gas-fueled burner in said oven comprising a sheet of metal extending across a major portion of the oven and mounted on said walls, said sheet having a burner box and integral venturi means stamped therein, said box and venturi means having one open side, and a refractory plate secured to the sheet in overlying relation to said open side of the box and venturi means and having a peripheral portion engaging the sheet throughout an area extending around said box and venturi means, said peripheral portion of the plate having a series of spaced portions which are raised out of contact with the sheet to provide ports communicating with the interior of the box.

9. An oven including a compartment defined by walls, a gas-fueled burner in said oven comprising a refractory sheet extending across a portion of the oven and mounted on said walls, a burner box having an open side, said box being secured to said sheet with the sheet closing the open side of the box, ports in said box communicating with the interior thereof, venturi means communicating with the interior of the box, and conduit means having one end disposed adjacent said venturi for delivering fuel to the venturi and consequently to the burner.

. UNITED STATES PATENT OFFER ERTWECATE OF CRECHN Patent No. 5,739, 766 Dated June 19 1973 Inventor(s) Peter lgeson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Claims Column 6, line 1, change "said" to side Signed and sealed this 5th day of February 1974.

(SEAL) Attest: ,7

EDWARD M.15LETCHER,JR. RENE D. TEGTMEYER Attesting Officer Acting Commissioner of Patents FORM PO-1D50(10-.69) I USCOMWDC 6037mm, k U.S, GOVERNMENT PRlNTING OFFICE: l9? 0-366-334 

1. An oven including a compartment defined by walls, a gasfueled burner in said oven comprising a refractory sheet extending across a major portion of the oven and mounted on said walls, a burner box having an open side with a flange extending outwardly therefrom, said box being secured to said sheet with the flange effectively engaging the sheet and the sheet closing the open side of the box, ports in said box communicating with the interior of the box, venturi means communicating with the interior of the box, and conduit means carried by the oven and having one end disposed adjacent said venturi for delivering fuel to the venturi and consequently to the burner.
 2. An oven as set forth in claim 1 wherein said ports are located between said sheet and flange.
 3. An oven as set forth in claim 1 wherein said box and sheet are of sheet metal, and said ports comprise stamped portions of the flange.
 4. An oven as set forth in claim 1 wherein said venturi means comprises at least in part a projecting portion of said box.
 5. An oven as set forth in claim 1 wherein said box and sheet are both sheet metal members, and said venturi means is an integral stamped part of one of said members.
 6. An oven as set forth in claim 1 wherein said burner box is a stamped sheet metal member and the venturi means is an integral stamped part at one end thereof, one side of the venturi means being open and continguous with the open side of the box and closed by said sheet, and said flange having spaced portions thereof raised out of engagement with the sheet to provide said ports.
 7. An oven as set forth in claim 1 wherein said oven walls include a front wall having a door therein, said walls, back and top walls, and an oven bottom spaced upwardly from the lower end of the compartment, and said sheet comprises a floor shield with the burner box located on it between the sheet and the oven bottom.
 8. An oven including a compartment defined by walls, a gas-fueled burner in said oven comprising a sheet of metal extending across a major portion of the oven and mounted on said walls, said sheet having a burner box and integral venturi means stamped therein, said box and venturi means having one open side, and a refractory platE secured to the sheet in overlying relation to said open side of the box and venturi means and having a peripheral portion engaging the sheet throughout an area extending around said box and venturi means, said peripheral portion of the plate having a series of spaced portions which are raised out of contact with the sheet to provide ports communicating with the interior of the box.
 9. An oven including a compartment defined by walls, a gas-fueled burner in said oven comprising a refractory sheet extending across a portion of the oven and mounted on said walls, a burner box having an open side, said box being secured to said sheet with the sheet closing the open side of the box, ports in said box communicating with the interior thereof, venturi means communicating with the interior of the box, and conduit means having one end disposed adjacent said venturi for delivering fuel to the venturi and consequently to the burner. 